Effects of clipping frequency on tiller development of crested wheatgrass and hybrid bromegrass at vegetative and reproductive stages

Information on the tiller development of hybrid bromegrass (Bromus inermis × Bromus riparius Rehm) is limited. The objective of this study was to evaluate the effect of clipping frequency at the vegetative and reproductive stages on the tiller development and concentrations of sugars of ‘AC Knowles’ hybrid bromegrass compared to ‘Kirk’ crested wheatgrass (Agropyron cristatum L.). This experiment was conducted in the greenhouse using the tillers of the vernalized plants dug from the field. The experimental design was a randomized complete block design. Grasses were clipped once or four times at either vegetative or reproductive stage. Regardless of the growth stage, four clippings reduced the tiller number of hybrid bromegrass by 25.9% compared to the undefoliated control while single clipping had no impact. The four clipping had no impact on the tiller number of crested wheatgrass, while single clipping increased its tiller number on average by 50.4% at both growth stages. Crested wheatgrass produced 16.6% more tillers than hybrid bromegrass under the single clipping. The two grass species had a similar number of axillary buds under different clipping treatments. The axillary bud size of crested wheatgrass was larger than hybrid bromegrass. All axillary buds were viable under the two clipping treatments for both grasses. Four clippings significantly decreased the stem base glucose concentration of the two grasses and the root sucrose concentration of crested wheatgrass. Hybrid bromegrass was less tolerant to frequent clippings than crested wheatgrass. Therefore, intensive grazing of hybrid bromegrass pasture may result in a thin stand.

The productive potential of the collection samples of the crested wheatgrass in the conditions of the Stavropol kray

The practice of using collection material in the breeding of forage crops has long been relevant and one of the most effective methods for identifying genetic sources of economically valuable traits for breeding new highly productive varieties adapted to local environmental conditions. The purpose of the current study was to create and identify a new promising initial material for breeding crested wheatgrass for productivity in the North Caucasus region. Productivity improvement is the main concern of plant breeding, which all other specific directions are subordinate to. The study was carried out in 2017–2020. The objects of the study were 31 varieties of various ecological and geographical origin taken from the world collection of the All-Russian Research Institute of Plant Production named after N.I. Vavilov and 13 varieties developed by the Stavropol Research Institute of Agriculture, including the variety ‘Vikrav’, approved for use in the North Caucasus region as a hay and pasture grain crop in 1994. The trial was laid in fallow, in a single repetition, the accounting plot area was 1.75 m2 . According to the green and hay mass productivity, there have been identified 7 samples, they are ‘K-50974’ (from the Ukrainian village of Petrovsky), three wild-growing samples ‘K-52357’ (from Ukraine), ‘K-51330’ (from the Chelyabinsk region) and ‘K-52441’ (from Kazakhstan) and three samples ‘2/2–18’, ‘4/2–18’, ‘6/2–18’ (developed by the SNIISKh). According to seed productivity there have been distinguished 9 samples ‘K-50974’ (from the Ukrainian village of Petrovsky), four wild-growing samples ‘K-52357’, ‘K-51330’, ‘K-52441’, ‘K-51104’ and three samples ‘2/2–18’, ‘4/2–18’, ‘6/2–18’ (developed by the SNIISKh). According to the complex of the above described traits there have been identified 5 samples.

Influence of Crested Wheatgrass on Soil Water Repellency in Comparison to Native Grass Mix and Annual Spring Wheat Cropping

Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) is a common introduced grass in the Canadian prairies, but concerns remain about its possible long-term effects on soil quality, and its influence on soil water repellency (SWR) has not been determined. The long-term (24 yr) effects of crested wheatgrass on soil water repellency (SWR) in comparison to seeded native grasses and annual cropping were determined for a clay loam soil in southern Alberta, Canada by measuring SOC concentration and SWR using soil hydrophobicity (SH) and soil water repellency index (RI) methods. The cropping treatments were crested wheat grass, seeded native grass mix, continuous wheat, and wheat-fallow rotation, each with fertilized (nitrogen) and non-fertilized sub-plots, replicated four times. Mean SOC concentration, SH, and RI in samples of surface soil were similar (P > 0.05) for crested wheatgrass and seeded native grass mix; and did not support our hypothesis (seeded native grass mix>crested wheatgrass). Mean SOC was significantly greater for seeded perennial grasses than annual crops by 1.7 to 2 times and SH by 2.1-2.5 times, which supported our hypothesis, but RI was similar among treatments. As expected, nitrogen fertilization significantly increased SOC concentrations, but the effects on SH and RI were undetectable. A strong positive correlation occurred between SOC concentration and SH (r=0.92), but not for RI (r=0.10). Our findings suggested that SWR was similar for crested wheatgrasses and seeded native grass mix. The SWR as measured using SH was greater for seeded perennial grasses than annual cropping, but was similar using RI.

Results of studying wheatgrass (AgropyronGaertn.) accessions from the VIR global genetic resources collection in Yakutia

With the globally changing climate, researchers seek to use plants adapted to extreme environments in breeding and genetic programs. As a forage crop, the wheatgrass from the genus AgropyronGaertn. is most suitable for such purposes.The area of temperature distribution for wheatgrass lies in the range from +42 (arid zone) to –60°C (Verkhoyansk). The use of different wheatgrass species as a crop for arid conditions is quite profoundly studied in the USA, Canada, Russia, and Kazakhstan. Genetic and breeding studies are underway in different countries. In Yakutia, with its extremely continental climate, wheatgrass has not yet been introduced as a crop, although it could play an important role in establishing a sustainable fodder reserve.The aim of the work was to study and select promising breeding source material, identifying germplasm with the best agronomic traits. As a result of a two-year study of 19 accessions of different wheatgrass species from the collection of VIR, undertaken in 2018 and 2019 in the collection nursery in Central Yakutia, plant forms were selected that exceeded the average green biomass yield for two cuts: k-52382 (wild crested wheatgrass, Pavlodar Region, Kazakhstan) by 43%, and k-48705 (wild-growing Kerch wheatgrass) by 40%. Besides, wild wheatgrass accession k-52382 was identified for its dry matter yield (40.2% higher than the average) and for the total green and dry matter yield for the two cuts (212.7 g/plant).Accessions k-52440 (wild Siberian wheatgrass, Stavropol Territory) and k-51330 (crested wheatgrass, Chelyabinsk Province) were selected for their high seed yield (43.5 g/m² and 41.7 g/m², respectively). The content of crude and digestible protein was the highest in k-50857 (crested wheatgrass cv. ‘Ephraim’, USA) and k-50858 (Siberian wheatgrass cv. ‘Vavilov II’, USA): 14.6% and 99 g/kg of feed, and 14.2% and 96 g/kg of feed, respectively. Winter hardiness of 12 accessions turned out to be 100%, with 80% in another 7 accessions.

Realizing productive capacity of crested wheatgrass varieties in the southern forest-steppe of the Bashkortostan Republic

Crested wheatgrass being high drought-resistant, is a promising forage crop for the Republic of Bashkortostan. It is relevant in developing varieties adapted to the environmental stress factors that have productive longevity, increased seed and fodder productivity. The paper presents the research results of crested wheatgrass varieties conducted in the nursery of competitive variety testing for seed productivity in 2018-2020. High seed productivity due to well-developed tillering capacity, powerful heads and large seeds of cultivars like Batyr, Brodskii crested, Parkway indicate their adaptation to local conditions and make them promising varieties for further study.

Sagebrush bird communities differ with varying levels of crested wheatgrass invasion

Sagebrush communities, covering millions of hectares in the western United States, are among our most imperiled ecosystems. They are challenged by various anthropogenic stressors, including invasion by non-native grasses, which degrade habitat quality and alter ecosystem function. Sagebrush restoration efforts are being undertaken to improve habitat conditions to benefit a wide range of sagebrush-dependent species. Because birds are good indicators of habitat quality, monitoring avian metrics is an effective way to measure progress of sagebrush restoration. We compared avian community composition and individual species abundance among three sagebrush-steppe habitat types with varying degrees of invasion by non-native crested wheatgrass Agropyron cristatum at the Camas National Wildlife Refuge in eastern Idaho. Sagebrush-obligate birds, such as sage thrasher Oreoscoptes montanus and sagebrush sparrow Artemisiospiza nevadensis, were most abundant in sagebrush habitats with an understory of native grass. Community composition was similar between sagebrush habitats with native and non-native grasses, but quite different from bird communities occupying crested wheatgrass. HABPOPS, a conservation planning tool, predicts that restoration of crested wheatgrass sites to sagebrush in poor or fair condition will increase the density of sagebrush-obligate bird species. Taken together, these results suggest that restoration of crested wheatgrass near-monocultures back to sagebrush will improve habitat value for much of the bird community whether or not the understory can be converted to primarily native grasses, or a mix of natives and non-natives. Of the sagebrush bird species of concern, Brewer’s sparrow Spizella breweri occupied sagebrush habitats with native vs. non-native understory at similar abundances, and this species could serve as a metric of intermediate restoration success. However, sagebrush sparrow and sage thrasher, which were significant indicators of sagebrush with native grasses, will likely benefit most from full restoration of a native herbaceous understory. Grassland-obligate birds like horned lark Eremophila alpestris and grasshopper sparrow Ammodramus savannarum were most abundant at crested wheatgrass-dominated sites and may not benefit from restoration back to shrubland; managers should understand potential trade-offs.

EVALUATION OF WILD-GROWING FORMS OF CRESTED WHEATGRASS WHEN USING IN BREEDING

The practice of using wild-growing material in the breeding of forage crops has long been recognized as a relevant and effective method for creating new varieties. The purpose of the research was to assess wild-growing samples of the crested wheatgrass and isolate genetic sources of economically valuable traits for breeding in the Stavropol Territory. The research was carried out in 2017–2020. The material of the study – 22 wild specimens of crested wheatgrass (Agropyron pectiniforme Roem. et Shult.) of various ecological and geographical origin. The crested wheatgrass variety ‘Vikrav’ served as the standard. During the years of study, meteorological conditions were extremely dry. The assessment of the samples was carried out according to the guidelines for the selection of perennial cereal grasses. The experiment was laid on bare fallow, plot area – 3 m2. Sowing and maintenance work were carried out manually. On average, for three years (2018–2020), the yield of green mass of the studied samples ranged from 0.15 to 0.94 kg/m2; dry – from 0.07 to 0.38 kg/m2; seeds – from 0.015 to 0.070 kg/m2. Samples from Ukraine (d.d. 28, 30), Chelyabinsk region (d. 31) and Kazakhstan (d.d. 34 and 37) were more productive in terms of fodder weight. In terms of seed productivity, in the first year, wild samples from Aktobe (d. 5) and Chelyabinsk regions (d. 31), from Ukraine (d. 25) and Kazakhstan (d.d. 34 and 37) were distinguished. In the second year of herbage use – from the Chelyabinsk region (d. 31) and Kazakhstan (d.d. 35 and 37). In the third year of use, no significant excess over the standard was found. On average, over three years of use, wild specimens d. 31, d. 34, and d. 37 exceeded the standard in seed yield by 0.020-0.033 kg/m2. Wild specimens from the Chelyabinsk region (d. 31) and Kazakhstan (d. 34) were isolated according to the complex of valuable characteristics for use in breeding in the Stavropol Territory.